For many years, practitioners in the medical treatment and medical device arts have endeavored to provide artificial heart devices constructed to replace a failed or failing heart within a recipient. The most basic long term need is the creation of a replacement pumping device which is capable of performing the basic blood pumping and circulation functions of the natural heart.
Early attempts to provide a sustainable heart replacement were severely limited by the available technologies and the state of the art at that time. Devices proved to be generally too large and unwieldy and, for the most part, impractical. With the continuing advances in the related technologies and creative arts, heart replacement devices became smaller, more reliable and, in some instances, at least partially implantable within the recipient. Such “implantable” devices have generally remained hybrid devices in that the actual pump may be implanted within the recipient while additional support apparatus remains external to the patient and remains connected to the implanted device by a plurality of connecting wires and hoses.
One of the more recent attempts to provide a reliable and practical artificial heart device which embodies great promise, is shown in the above referenced and incorporated U.S. Pat. No. 9,314,559 which sets forth an artificial heart for use in a human recipient that includes a housing within which a quartet of turbine pump segments are operative. The quartet of turbine pump segments provides a redundancy which in turn enhances the safety factor provided by the artificial heart. A controller is powered by a rechargeable battery and is operative to apply appropriate drive signals to the motor drives of the turbine pump segments. The battery may be implanted along with the controller to avoid the need for any external connections to the artificial heart. An inductively coupled battery charger for use outside the recipient's body is positioned proximate the battery charger to provide inductively coupled charging for use in driving the artificial heart.
In a field of endeavor closely related to the attempts to provide a practical and reliable implantable artificial heart, practitioners have also been addressing the need for a ventricular assist device. Such ventricular assist devices (VADs) supplement the performance of a weakened heart without fully replacing it. Ventricular assist devices provide an implantable mechanical pump that helps blood flow from the lower chambers of a weakened heart, the ventricles, to other parts of the body or other parts of the heart itself. One of the most prevalent uses of such ventricular assist devices, known as LVAD, is implanted in the patient's chest cavity and is used to pump blood from the lower portion of the left ventricle to the heart aorta.
A successful ventricular assist device must, above all, be long lasting and reliable. The dire consequences to the device recipient brought about by device failure make this requirement all too apparent. In addition, however, the device must be small enough to be implantable within the recipient's chest and efficient enough to maintain adequate blood circulation to sustain normal life functions. The device must avoid undue stress upon the recipient's circulatory and pulmonary systems. The device must also be capable of adjusting to and compensating for different recipient activity levels and stress. Additional requirements such as avoidance of blood cell damage by the pumping apparatus and the prevention of blood clot forming stagnation regions make further demands upon ventricular assist devices.
While practitioners in the medical treatment and medical device arts have created a virtually endless number of proposed artificial ventricular assist devices, there remains nonetheless a continuing unresolved need in the art for an improved, implantable, reliable and effective artificial ventricular assist device which meets the stringent, unforgiving and vital requirements and challenges posed by a truly fully functioning completely implantable ventricular assist device.